1. Field of the Invention
This invention relates to a connector for electrically connecting a plurality of card-type electronic devices to a printed circuit board.
2. Prior Art
Conventionally, there has been proposed a card connector provided with two housings and a plurality of electrically conductive terminals (see Publication of Japanese Utility Model Registration No. 3027049 (Paragraph numbers [0010], [0012], and [0014]).
The two housings are formed separately from each other, but have the same shape. Each housing is comprised of a base portion, and side portions continuously extending from opposite ends of the base portion at right angles to the base portion. Each housing is U-shaped in plan view. The two housings are stacked one upon another in a manner directed in the same direction, and are formed with an over-molded portion such that they are formed as a unitary member.
A latch piece is integrally formed with a foremost end of each side portion of each housing. The latch pieces are engaged with side edges of a card (card-type electronic device) to hold the card.
The electrically conductive terminals are arranged at the base portions of the two housings at a predetermined pitch.
Each electrically conductive terminal is comprised of a contact portion, an intermediate portion, and a solder tail. The contact portion is caused to face a card insertion hole formed in the base portion of each housing. The intermediate portion connects the contact portion and the solder tail. The intermediate portion of each electrically conductive terminal of the upper housing extends from an outer surface of the base portion of the upper housing, then bent toward the lower housing, and further bent at right angles at a location close to a lower surface of the lower housing to extend away from the outer surface of the base portion of the lower housing. The solder tail is formed on one end of the intermediate portion, and is bent into the shape of a crank. The intermediate portion of each electrically conductive terminal of the lower housing extends from the outer surface of the base portion thereof, bent toward the lower surface of the base portion thereof, bent again toward the base portion at right angles at a location close to the lower surface of the base portion, and extends through the base portion to protrude from an inner surface thereof. The solder tail is formed on one end of the intermediate portion, and is bent into the shape of a crank.
To load a card in the connector, first, a front end of the card is inserted into the card insertion hole in the base portion at a predetermined angle.
Then, the side edges of the card are caused to be engaged with the associated latch pieces while pivoting the card with the front end thereof as the center of pivotal motion such that the insertion angle is reduced. When the latch pieces are engaged with the side edges of the card, the card is locked, which completes the operation of loading the card.
On the other hand, to remove the card from the connector, it is only required to disengage the card from the latch pieces, pivot the card through an angle substantially equal to the above-described insertion angle in a direction opposite to the direction of pivotal motion during the loading operation, and then pull the front end of the card out of the insertion hole.
The above-described connector is advantageous for high density mounting, since two cards opposed to each other can be connected to the circuit board.
In the connector, however, the intermediate portions of the electrically conductive terminals arranged in the upper housing, and the intermediate portions of the electrically conductive terminals arranged in the lower housing are close to each other.
This makes it difficult to perform impedance matching between the electrically conductive terminals arranged in the upper housing and the electrically conductive terminals arranged in the lower housing.